1. Technical Field
The present invention relates in general to directing the exhaust of an aircraft to improve its agility in flight and, in particular, to an improved system, method, and apparatus for control input prediction and state verification of a high performance aircraft's fluidic vectoring exhaust system.
2. Description of the Related Art
The exhaust nozzles of conventional jet aircraft typically direct the exhaust flow along a central axis of the nozzle. In order to improve the agility of high performance aircraft, vectoring nozzles have been used to redirect the exhaust slightly off-axis. Historically, vectoring nozzles have used mechanical systems to redirect the exhaust flow. Such mechanical systems usually employ plates or the like that are located adjacent to the nozzle to channel the exhaust flow in the desired direction. However, the need for aggressive next-generation designs with complex geometric shaping has placed an emphasis on moving away from mechanical systems.
One potential alternative to mechanical vectoring nozzles is fluidic vectoring nozzles. In contrast to most prior art designs, fluidic vectoring exhaust systems theoretically should not employ any mechanical moving parts to alter the direction of the exhaust plume, and therefore would have no physical surface deflection to measure and correlate to the desired vector state. Consequently, a significant problem encountered during the development of fluidic vectoring nozzles has centered on how to verify the vector state of the exhaust plume. An integrated flight control system would require both (1) a means for commanding a specific vector angle, and then (2) a means for verifying what vector angle resulted (i.e., feedback) to allow corrections so that the desired vector angle is actually produced. Thus, a solution for fluidic thrust vectoring exhaust systems that is non-intrusive and encompasses an exhaust vector state input prediction and verification scheme that can be implemented in a flight control system would be desirable.